Inviting people to a shared Photo Stream
I first spotted this bug when I first set-up a shared Photo Stream between me and the wife. The original Invite when I set the Photo Stream up never went through, so today I tried doing it again and it didn't go through.
Since Apple in their infinite wisdom never implemented a Delete Invite option I was unable to delete her Invite and start again.
the only way I could get the Invite to go through was to delete the Photo Stream and re-create it and her Invite went through and she was able to accept the Invite.
Adding Photos to a shared Photo Stream
Once I'd re-created the Photo Stream and added some Photos I was then unable to add anymore Photos or Videos, the Photos app would just freeze and I'd have to return back to my Home-screen & close the app through Multi Tasking.
the only way I could get Photos to add was to delete all the Photos in the Photo Stream and re-boot by holding down the Sleep/Lock button until the screen went blank and I was able to add Photos as normal.
I've got no idea if these are a bug or due to hardly ever re-booting my phone meaning that the RAM needed flushing by doing a re-boot.